Problem: $ \left(-\dfrac{9}{4} \div -\dfrac{5}{9}\right) \div \dfrac{5}{2} = {?} $
Dividing by a fraction is the same as multiply by the reciprocal of that fraction. $ = \left(-\dfrac{9}{4} \times -\dfrac{9}{5}\right) \div \dfrac{5}{2} $ $ = \left(\dfrac{-9 \times -9} {4 \times 5}\right) \div \dfrac{5}{2} $ $ = \dfrac{81}{20} \div \dfrac{5}{2} $ $ = \dfrac{81}{20} \times \dfrac{2}{5} $ $ = \dfrac{-81 \times 2}{-20 \times 5} $ $ = \dfrac{162}{100}$ Simplify: $ = \dfrac{81}{50}$